From gbhackers.com
Twitter Bug Exposed location Data of Some Users to Unknown Advertisers
Twitter disclosed a bug report that in certain conditions they have accidentally collected and shared the location data of iOS users to the advertisers, even if they opted not to share the data.
The data was collected in the condition; if the user used one or more twitter accounts on iOS devices and opted to collect the location data from one account, then the location data will be obtained from any other accounts used on that same device.